IS0 b 9 3 4853903 05273q2 466 I NT ER NAT I O NAL STANDARD IS0 6 Second edition 1993 02 01 Photography Black and white pictorial still camera negative film/process systems Determination of IS0 speed P[.]
IS0 b 4853903 05273q2 466 I NT ER NAT I O NAL STANDARD IS0 Second edition 1993-02-01 Photography - Black-and-white pictorial still camera negative film/process systems Determination of IS0 speed - Photographie - Systèmes filmltraitement négatifs noir et blanc pour photographie picturale - Détermination de la sensibilité IS0 Reference number I S 6:1993(E) IS0 b M 485LS03 0527143 3T2 IS0 6:1993(E) Foreword I S (the International Organization for Standardization) is a worldwide federation of national standards bodies (IS0 member bodies) The work of preparing International Standards is normally carried out through IS0 technical committees Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work I S collaborates closely with the International Electrotechnical Commission (IEC) on ali matters of electrotechnical standardization Draft International Standards adopted by the technical committees are circulated to the member bodies for voting Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote International Standard IS0 was prepared by Technical Committee ISO/TC 42, Photography This second edition cancels and replaces the first edition (is0 6:1974) The primary change is to eliminate the restriction that the I S speed of all black-and-white films be determined in a specified developer and fixing bath It also updates references, procedures and the format in accordance with more recent speed standards for other film types Annexes A and B of this International Standard are for information only I S 1993 All rights reserved No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher International Organization for Standardization Case Postale 56 CH-I 211 Genève 20 Switzerland Printed in Switzerland ii IS0 b Y853903 4 239 IS0 6:1993(E) Introduction Black-and-white films will generally provide excellent results in several different developers and processing conditions At the same time, it is realized that the speed of a film depends on the process used Therefore, this International Standard specifies a method for determining the photographic speed of film/process combinations This means a particular film may have several I S speeds associated with it depending on the processes used For this reason, it is important that manufacturers indicate the processing conditions for which I S speed values are quoted This International Standard recognizes that black-and-white films not generally have a unique speed if several different processes are recommended This conflicts with the tradition of associating a specific speed value with a particular product In the future, the process used for determining speed values should be unequivocally described to avoid misinterpretation Since users often not know how these films will be processed, manufacturers have an obligation to provide a speed value for this situation which will ensure good results Usually they will take advantage of the overexposure tonal latitude of the film and give it a conservative speed value to protect users from underexposure effects in case the film is put through a process which yields low speed It is recognized that the speed at which a film can be exposed is dependent on the extent of development, scene luminance range, subject matter, printing paper, etc This International Standard specifies that film/process speed is determined when the film is processed to obtain a specified contrast level The relative I S speed ranking of various films in different process systems will generally differ The I S speeds will provide correct exposures for average scenes with exposure meters conforming to I S 2720 or I S 2721 when the film is processed as specified in this International Standard iii IS0 b 93 W 4853903 0527345 375 I S 6:1993(EI INTERNATIONAL STANDARD - Photography Black-and-white pictorial still camera negative film/process systems Determination of IS0 speed - Scope Definitions This International Standard specifies the method for determining the I S speed of black-and-white negative camera films used for pictorial still photography For the purposes of this International Standard, the following definitions apply This International Standard applies to films processed in conventional chemicals and equipment, but also to those processed using special procedures such as those involving activators or heat for development This International Standard does not apply to motionpicture, aerial photography, graphic arts, radiographic or micrographic applications, nor to negatives produced in diffusion transfer systems 3.1 exposure, H: The time integral of illuminance on the film, measured in lux seconds Amounts of exposure are often expressed in logarithmic terms (log,&) 3.2 speed: A quantitative measure of the response of the photographic material to radiant energy for the specified conditions of exposure, processing and image measurement Sampling and storage Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard At the time of publication, the editions indicated were valid All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below Members of IEC and I S maintain registers of currently valid International Standards I S 5-2:1991, Photography - Density measurements Part 2: Geometric conditions for transmission density, - I S 5-3:1984, Photography - Density measurements - Part 3: Spectral conditions I S 7589:1984, Photography - Illuminants for sensitometry - Specifications for daylight and incandescent tungsten In determining the I S speed of a product, it is important that the evaluated samples yield the average results obtained by users This will require evaluating several different batches periodically under the conditions specified in this International Standard Prior to evaluation, the samples shall be stored according to the manufacturers' recommendations for a length of time to simulate the average age at which the product is normally used Several independent evaluations shall be made to ensure the proper calibration of equipment and processes The basic objective in selecting and storing samples as described above is to ensure the film characteristics are representative of those obtained by a photographer at the time of use Test method 5.1 Principle Samples are exposed and processed as specified b e low Density measurements are obtained from the resultant images to produce a sensitometric curve from which values are taken and used to determine I S speed IS0 b 93 W 4851903 0527346 005 IS0 6:1993(E) 5.2 Safelights 5.3.6 Exposure time To eliminate the possibility of unintentional exposure to radiation affecting the sensitometric results, all films shall be handled in complete darkness during sample preparation and processing The exposure time shall be between s and 1/1 O00 s corresponding to the usage practice for the particular film tested Since the speed of film is d e pendent on exposure time because of reciprocity law failure, the exposure time used for determining IS0 speed should be specified in use instructions 5.3 Exposure 5.3.1 Conditioning of specimens During exposure, the specimens shall be kept at a temperature of 23 O C f O C and a relative humidity of (50 f 5) % 5.4 Processing 5.3.2 Type of sensitometer The sensitometer shall be a illuminance-scale type non-intermittent, 5.3.3 Radiant energy quality The appropriate illuminant for the particular film type being exposed shall conform to the specifications given in I S 7589 I S speed may be determined using I S Sensitometric daylight, studio tungsten or photoflood illuminants Since the speed of film/process combinations will depend on the type of illuminant used for determining IS0 speed, the illuminant should be specified in use instructions 5.3.4 Filters I S speed shall be specified for use without a filter in front of the camera lens If film is used with a colour filter in front of the camera lens, an "equivalent" speed number can be used to determine the exposure of the film with the filter I S speed does not apply to the filtered conditions 5.3.5 Modulation The total range of spectral diffuse transmission density of each area of the light modulator throughout the wavelength interval from 400 nm to 700 nm shall not exceed % of the average density obtained over the same interval or a value of 0,03,whichever is greater In the interval from 360 nm to 400 nm, 10 % of this same average density, or a value of 0,06,whichever is greater, shall not be exceeded If stepped increments are used, the base 1O logarithm of the exposure increment shall not be greater than 0,20 The width and length of a single step shall be adequate to obtain a uniform density within the reading aperture specified for densitometry If a continuous variable modulator is used, the base 10 logarithm of the change in exposure with distance along the test strip shall be uniform and not be greater than 0,04per millimetre 5.4.1 Conditioning of speclmens In the time interval between exposure and processing, the specimens shall be kept at 23 OC f O C and at a relative humidity of (50 f 5) % The processing shall be completed in not less than days and not more than 10 days after exposure for general-purpose films, and not less than hours and not more than days after exposure for professional films 5.4.2 Processing speciflcations The only processing specification required in this International Standard is that the density difference between points m and n shall be 0,80 (see 5.6.3 and figure 1) No additional processing specifications are included in recognition of the wide range of chemicals and equipment used in processing black-and-white films I S speeds provided by film manufacturers generally apply to films when they are processed in accordance with their recommendations to produce the photographic characteristics specified for the process Process information shall be available from film manufacturers or others who quote I S speed This shall specify the chemicals, time, temperatures, agitation equipment and procedure used for each of the processing steps and any additional information required to obtain the sensitometric results described The values for speed obtained using various processing procedures can differ significantly Although different speeds for a particular film can be achieved by varying the process, other sensitometric and physical changes can also accompany the speed changes Generaliy, processes which yield higher I S speed will also increase the graininess of the negative and the final print IS0 6:1993(E) ? a s t VI c U u -c - n VI E, c e + N ' E x I- U L d U c E c VI O v, Density o f base I - -3.0 I - -2,o I Log& 5.5 I -1.0 O L09lOH" - Method for determining speed Densitometry IS0 standard Type diffuse transmission density of the processed images shall be measured using a densitometer complying with the geometric conditions specified in I S 5-2 and spectral conditions specified in I S 5-3 Readings shall be made in a uniform area of the image 5.6 fo 1,30 Lo910Hm Figure + Evaluation 5.6.1 Sensitometric cuwe The I S standard Type diffuse transmission density values are plotted against the base 1O logarithm of the corresponding exposure, H , expressed in lux seconds, to obtain a sensitometric curve similar to that illustrated in figure posure is 1,30 units greater than that at point m The development time of the negative material is so chosen that the density difference, AD, between points m and n is 0,80 (see annex A) Then, H,,,, represents the exposure, in lux seconds, corresponding to point m when the above condition is satisfied Product classification 6.1 I S speed scale The arithmetic speeds, S, and the logarithmic speeds, So, given in table are derived from the following equations S = - 0,80 Hrn so = + 10 log,,H, 0,80 5.6.2 Base-plus-fog density The combination of base and fog density shall be determined from an unexposed sample of the same film processed simultaneously with the film exposed for determining the sensitometric curve I S speed shall be obtained directly from log,, H, by use of table1 which shows the rounded values of S and So to be used 6.2 IS0 speed of a product 5.6.3 Determination of H , The method for determining speed is illustrated in figure I.Point m is located on the curve at a density of 0,lO above base plus fog density Point n is located on the curve where the base 10 logarithm of the ex- The I S speed of a product (as distinguished from that of a specific sample) shall be based on the arithmetic mean of the values of log,, H,, determined from various batches of the product when selected, stored and tested as specified above The IS0 speed IS0 b U 4851903 0527148 984 IS0 6:1993(E) of a product with proper rounding is then determined from the mean value of log,, H, using table IS0 speed log,, Hin from to - 3,65 3,56 3,46 - 3.55 - 3,45 - 3,35 - 3,25 - 3,15 - 3,05 - 2,95 - 2,85 - 2,75 - 2,65 - 2,55 - 2,45 - 2,35 - 2,25 - 2,15 - 2,05 -I,% - 1,85 - 1,75 - 1,s - 1,55 - 1,45 - li35 - 1;25 Since I S speed is dependent on the exposing and processing conditions, these should be indicated when quoting I S speed values - 3,36 - 3,26 -3,16 - 3,06 - 2,96 - 2,86 - 2,76 - 2.66 - 2.56 - 2,46 - 2,36 - 2.26 - 2,16 - 2.06 - 1.96 - 1,8a - 1,76 - 1,66 - 1,56 - 1,46 - 1,36 - 1.26 - 1,16 6.3 Accuracy S s" 200 500 O00 1600 250 36" 35" 34" 33" 32" The calibration of the equipment and processes involved in determining film speed shall be adequate to ensure that the error in log,, H, is less than 0.05 O00 800 640 500 400 31O 30" 29" 28" 27" Product marking and labelling 320 250 200 160 125 26" 25" 24" 23" 22" 1O0 80 64 50 40 21 O 20" 9" 18" 17" 32 25 20 16 12 16" 15" 14" 13" 12" Speed of a product, determined in accordance with this International Standard and expressed on the scales of table 1, may be designated I S speed and denoted in one of the following forms: a) by its arithmetic speed , e.g I S 100; b) by its logarithmic speed, e.g IS0 21'; c) by both its arithmetic and its logarithmic speed, e.g I S 100/21° However, since the speed is dependent on the illuminant, exposure time and process used, these conditions should be clearly indicated whenever practical when quoting values to avoid misinterpretation ~ ~~ 4853903 0527349 810 M IS0 b 93 I S 6:1993(E) Annex A (in f or mat ive) Suggested method of determining log,, H , The value of loglo H , can be determined by plotting loglo H , at a point where the density is 0,lO above base plus fog density, against AD,the difference in density between this point and a point where the base 10 logarithm of the exposure is 1,30 units greater This is then repeated for a development series Draw a smooth curve through the points Determine the loglo H corresponding to AD = 0,80 which is designated log10 H, 1250 -3.25 I 1000 I I 800 I 640 -3,05 -2.85 LogioH Figure A.l I I I 500 I 400; I I -2.65 320 I 250 I 200 I 260 I -2.45 -2,25 Lo910Hrn - Method of determining loglo H, IS0 b 93 m Liâ5Lï03 0527L50 532 m IS0 6:1993(E) Annex B (informative) Bibliography - [l] IS0 5-1:19$4, Photography measurements notations - Part Density I: Terms, symbols and - Specifications CS] I S 2720:1974, Photography - General purpose photographic exposure meters Iphotoelectrie type) Guide to product specification - - Automatic controls of exposure Cameras - [5] IS0 5800:1987,Photography - Colour negative [Z] I S 554:1976, Standard atmospheres for conditioning and/or testing [4] IS0 2721:1982, Photography films for still photography IS0 speed - Determination of [6] IS0 6846:1992,Photography - Black-and-white - Determination of IS0 continuous-tonepapers speed and IS0 range for printing _. _ IS0 b - 4851903 052715L 479 W I S 6:1993(E) UDC 771.534.51 Descriptors: photography black-and-white photography, photographic film, photographic emulsions, tests, determination, sensitivity (photography) Price based on pages